Designing a cellular IoT device often turns into a layered hardware stack: LTE modem + microcontroller + power circuitry + antennas. While this works, it increases cost, complexity, and power consumption.
Open Stack takes a different approach.
Instead of pairing an LTE modem with an external controller, Open Stack runs applications directly on the cellular module itself. The result? A compact, power-efficient, production-ready LTE IoT platform that eliminates the need for an Arduino, ESP32, or Raspberry Pi.
Built Around the Quectel EC200U LTE Module
At the core of the board is the Quectel EC200U-CN LTE module. Unlike traditional “data-only” LTE modems, this module can execute RTOS-based C applications directly on its internal Arm processor.
That means:
- No external MCU required
- Lower power consumption
- Reduced BOM cost
- Smaller overall device footprint
For developers building commercial IoT deployments, this architecture simplifies both prototyping and production.
Connectivity & Wireless Capabilities
Open Stack supports a wide range of communication technologies:
Cellular
- LTE FDD bands: B1, B3, B5, B8
- LTE TDD bands: B34, B38, B39, B40, B41
- GSM fallback: 900 / 1800 MHz
- Data rates up to 10 Mbps (download) and 5 Mbps (upload)
GNSS Positioning
- GPS
- GLONASS
- Galileo
- BeiDou (BDS)
- QZSS
Bluetooth
- Bluetooth 4.2 (BR/EDR + BLE)
With built-in GNSS and LTE on the same board, it’s well suited for tracking systems, remote monitoring, and mobile deployments.
Networking Stack & Server Mode
Open Stack includes full IPv4 and IPv6 support and can operate as a client or standalone server over the cellular network.
Supported protocols include:
- TCP / UDP
- SSL / TLS
- HTTP / HTTPS
- MQTT
- LwM2M
- CoAP
- FTP / FTPS
- PPP
Server mode capability allows external devices to connect directly over LTE (carrier permitting), making it useful for remote endpoints, telemetry systems, and industrial monitoring nodes.
Raspberry Pi HAT Compatibility (Without the Pi)
The board features a 40-pin expansion header aligned with the standard layout defined by the Raspberry Pi Foundation.
This allows many Raspberry Pi HATs to interface directly with Open Stack — without requiring a Raspberry Pi SBC in the system.
For developers already invested in the Raspberry Pi hardware ecosystem, this dramatically shortens development time.
Hardware Overview
Additional onboard features include:
- 128×32 OLED display
- 3× U.FL antenna connectors (LTE, GNSS, Bluetooth)
- USB Type-C port for power, programming, and debugging
- Nano SIM card slot
- Boot, reset, and user buttons
- Network and status LEDs
- Operating temperature (module): -40°C to +85°C
The board is clearly positioned for both field deployment and industrial use cases.
Development Environment
Programming is done using the QuecOpen SDK, which enables C-based development directly on the LTE module. Developers gain access to:
- I2C
- SPI
- UART
- PWM
- Full networking stack
For simpler applications, AT commands can be issued via USB-C.
The project is described as open-source, with hardware design files expected to be released after the crowdfunding campaign concludes.
Regional LTE Band Considerations
The EC200U-CN module is primarily targeted at China and India. Other regional variants such as EC200U-EU and EC200U-AU exist for different markets, but availability for this board should be verified.
There is currently no EC200U-NA variant for North America, so users should confirm LTE band compatibility with their carrier before deployment.
Open Stack differs by removing that layer entirely, making it architecturally closer to solutions like the Waveshare EC200U C4-P01 — but positioned as a standalone IoT connectivity platform ready for direct RTOS deployment.
If all of this appeals to you as much as I do, you have until March 11th to support the Open Stack Kickstarter project. An Open Stack board costs €55 (about $66 USD) to backers, and adding a GPS antenna costs a few additional dollars. April is when rewards should ship.
